The use of small diameter nozzles in temperature-controlled hemp oil extraction allows high oil yields and good quality residual hemp cake feed.

The use of two nozzle diameters (6 and 8 mm) in a cold (50°C) hemp seed oil extraction process was evaluated in terms of extraction efficiency, and chemical composition and in vitro fermentation characteristics of the residual cake. Seeds of the varieties Futura 75 and Uso 31 were pressed using a mechanical press with a cooling device. Five pressings were carried out for each variety and nozzle size, the functional parameters of the extraction processes were recorded, and sample of the residual cakes (n = 20) were analyzed. The 6 mm nozzle determined a higher oil yield (+4%) with a limited increase in temperature in the pressing chamber and in the oil (on average + 3°C compared to the 8 mm nozzle). A lower oil yield and consequently a higher fat content in the corresponding cake was observed when using the 8 mm nozzle. Despite the similar fat content, the two varieties had different oil yields and different residual cake compositions. The gas production kinetic of cakes was influenced by variety but little by nozzle size. Overall, the use of a smaller nozzle in a temperature-controlled extraction process can be a useful option to increase hemp oil yield while maintaining good fermentation characteristics of the residual cakes as ruminant feed.

Nutritional Characterization of Hay Produced in Campania Region: Analysis by the near Infrared Spectroscopy (NIRS) Technology.

Since the dietary characteristics of hays can be very variable, it is of great importance for nutritionists to know their chemical composition in order to formulate adequate rations for the animals. Laboratory analyses are time-consuming and expensive while the Near Infrared Spectroscopy offers several advantages, including obtaining information on feeds nutritional characteristics very quickly and in situ at the farm, thanks to portable NIRS. In this trial, over 400 hay samples collected in the Campania region (Italy) were analyzed with portable NIRS device. The final aim was to analyze the differences in hay quality in different production areas, highlighting the possible factors involved and suggesting possible corrective measures. All the analyzed hays (polyphite, Gramineae and alfalfa) were significantly (p < 0.05) influenced by the area of cultivation/preservation. In particular, the polyphite and Gramineae hays produced in most of the areas of Campania region showed poor nutritional value due to the low protein content and high structural carbohydrate that significantly reduced its digestibility. The use of high-quality forages in the ration represents a pivotal factor to allow the production of high-quality products of animal origin. The use of NIRS seems to be a valuable strategy to select potential treatments that can increase feed digestibility and to avoid long chemical analysis.

Development of a laboratory technique for the evaluation of protease enzymes activity in goat and sheep milk.

The shelf life of milk and its products is strongly influenced by the quality of raw milk. Several bacteria present in raw milk can produce proteases: among them, those from psychotropic microorganisms (e.g. Bacillus subtilis), which produce enzymes under refrigeration, cause the most serious problem. The interaction of these enzymes with the milk proteins and the main proteolytic enzymes becomes important in determining the quality of the milk. An artificial substrate (azocasein) was used to quantify the enzyme activity through the release of a chromogenic product that was measured spectrophotometrically after clarifying the sample by the addition of trichloroacetic acid. The detection limit and quantification limit were 1.43 and 4.77mg/ml respectively for sheep milk and, 2.25 and 7.5mg/ml respectively for goat milk. This method is useful for determining the proteolytic activity in different media and its effectiveness depends on chemical-nutritional characteristics of the sample.

Effects of feeding Mediterranean buffalo sorghum silage versus maize silage on the rumen microbiota and milk fatty acid content.

Sorghum presents a sustainable feedstock for Mediterranean buffaloes due to its reduced water and nitrogen requirements compared with maize, which is currently fed primarily. We investigated the effects of feeding sorghum as opposed to maize on Mediterranean buffalo rumen microbial diversity and milk fatty acid content. Four cannulated lactating Mediterranean buffalo cows were fed a basal diet for one month before switching either to maize or sorghum-silage based diets for a 3-month period. Buffaloes were then changed over to the contrasting diet for a further one month. Rumen and milk samples were collected at the end of each month. DGGE- and T-RFLP-based dendrograms generated from rumen samples did not show an effect of diet on rumen bacterial diversity. Milk samples also did not differ in terms of their fatty acid content post sorghum feeding as compared with maize feeding. Thus, sorghum provides an environmentally beneficial alternative to maize for feeding Mediterranean buffalo with little effect on rumen microbial diversity or milk fatty acid composition compared with maize feeding.

Effect of dioxin exposure on several indices of blood redox status in lactating buffalo cows.

Dioxins are lipophilic compounds with a small molecular weight and are highly persistent, bioaccumulative and toxic. Dioxin detoxification is associated with an increased production of reactive oxygen species (ROS). In physiological conditions the body is protected against ROS and their toxic products by a wide range of antioxidant systems. We hypothesize that the imbalance between ROS production, associated with dioxin exposure, and the antioxidant defence capacity, may lead to oxidative stress, with consequent increased consumption of antioxidants and accumulation of toxic compounds in blood and tissues. The objective of this study was to evaluate the effect of exposure to dioxins on the plasma redox status of lactating buffalo cows. To this aim, the major liposoluble (retinol and α-tocopherol) and water-soluble (ascorbate) antioxidants, the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, the total antioxidant capacity (TAC), as well as specific protein oxidation markers (protein bound carbonyls and nitro-tyrosine) and lipid oxidation markers (hydroperoxides), were chosen as indices of blood redox status. The concentration of antioxidants, protein-bound carbonyls (PC), nitro-tyrosine (N-Tyr), and hydroperoxides (LPO), the SOD and GPx activity, and the TAC were measured in plasma samples obtained from buffalo cows exposed to environmental levels of dioxins higher (n=21, group A) or lower (n=29; group B) than those permitted. Plasma titres of antioxidants, as measured by HPLC, and the total antioxidant capacity, as measured by trolox equivalents capacity, were higher in group B than in A. Similarly, SOD and GPx activities were higher in group B than in A. Conversely, plasma levels of PC, N-Tyr and LPO, as measured by ELISA, were higher in group A than in B. Our results suggest that exposure to dioxins impairs the plasma antioxidant defence system of lactating buffalo cows, and that metabolic processes associated with dioxin detoxification might induce or enhance oxidation of protein and lipids. This adverse effect on blood redox status might have negative implications for animal health and reproduction, and might compromise animal welfare.